Basic parts of a disc drive generally include a disc that is rotated, an actuator that moves a transducer to various locations over the disc, and electrical circuitry that is used to write and read data to and from the disc. Typically, the transducer functions with the electrical circuitry, translating electrical signals into magnetic field signals for recording data “bits” to the disc, or vice versa for reading data “bits” from the disc.
The transducer is generally housed within a small ceramic block known as a slider, with the slider being passed over the rotating disc at a certain fly height. Generally, greater performance of the disc drive results when the slider is flown as closely to the surface of the disc as possible. In operation, the distance between the slider and the disc, or “fly” heights or head media spacing, can be in the range of micro inches. It is contemplated that fly heights will continue to be reduced, for this is one factor in achieving increased recording density. However, this will require considerable care or else head/media intermittent contact can result. Such contact induces vibrations detrimental to the reading/writing quality at such low fly height, and can also eventually result in a head crash and total loss of data.
One manner by which head media spacing has been decreased to date is via shaping the alumina located at the trailing edge of the slider. Typically, the slider is formed from a wafer of ceramic material. The transducer or transducers (separate read and write elements) are placed onto the wafer and then encased in alumina. Once encased, the wafer is diced to form individual heads, and then the alumina is shaped to include various features. Shaping the alumina at the trailing end of the slider can be beneficial in enabling the head to fly at decreased spacing with respect to the media. However, the conventional shaping process can result in alumina features being inconsistently formed from head to head. Such inconsistency can in turn lead to undesirable variance in fly height from slider to slider. A reason for such variance is that the alumina features are formed at the bar level, or after the wafer has been cut into individual heads. Consequently, the corresponding cuts are often found to vary from head to head, leading to inconsistency in fly heights for the heads, and inconsistent results being obtained during reading and recording of data.